IBM® App Connect Enterprise can provide an embedded WebSphere® eXtreme
Scale grid. You can also connect to an external WebSphere eXtreme
Scale grid.
The embedded WXS grid can be used by message flows running in any integration
server, and you can set properties explicitly for each integration server. The examples in this
section show integration servers that are managed by an integration node; however, the embedded WXS
grid can also be used by independent integration servers, which are not managed by an integration
node.
The following diagram shows the embedded WXS grid in an integration node that contains six
integration servers. Four integration servers host components for the embedded WXS grid, but message
flows in all six integration servers can use the cache.
The following diagram shows how
IBM App Connect Enterprise can connect to both an
embedded WXS grid and an external
WebSphere eXtreme
Scale grid. A policy is used to
connect to the external grid.
The following components are involved in the embedded WXS grid:
- Catalog servers
- The catalog server is a component that is embedded in an integration server, and it controls the
placement of data and monitors the health of containers. You must have at least one catalog server
in your embedded WXS grid.
To avoid losing cache data when a catalog server is lost, you can
specify more than one catalog server. If the cache is shared by two integration servers, each of
which hosts a catalog server, if one catalog server fails, the remaining catalog server can still be
accessed. Having more than one catalog server can affect startup time until the cache is
available.
When you are using multiple catalog servers, you can improve performance by taking
the following steps:
- Provide other integration servers that host container servers only, rather than having only
integration servers that host both catalog and container servers.
- Start and stop integration servers in sequence, rather than using the mqsistart or mqsistop commands
to start or stop all integration servers at once. For example, start the integration servers that
host catalog servers before you start the integration servers that host only container servers.
- Container servers
- A container server is a component that is embedded in the integration server that holds a subset
of the cache data. Between them, all container servers in the embedded WXS grid host all of the
cache data at least once. If more than one container exists, the default cache policy ensures that
all data is replicated at least once. In this way, the embedded WXS grid can cope with the loss of
container servers without losing data.
You can host more than one container server in a
multi-instance integration node. If the active instance of the multi-instance integration node
fails, the embedded WXS grid switches to the container server in the standby
instance.
- Catalog domain name
- When you are using a embedded WXS grid that spans multiple integration nodes, ensure that all
WebSphere eXtreme
Scale servers that are clustered in one embedded grid use the same
domain name. Only servers with the same domain name can participate in the same grid. WebSphere eXtreme
Scale clients use the domain name to identify and distinguish between
embedded grids.
Servers in different domains cannot collaborate in the same
grid.
- Grids
- WebSphere eXtreme
Scale provides a scalable, in-memory data grid. The data grid
dynamically caches, partitions, replicates, and manages data across multiple servers. The catalog
servers and container servers collaborate to act as an embedded WebSphere eXtreme
Scale grid. For more information about grids, see WebSphere Extreme
Scale product documentation online.
- Maps
- Data is stored in maps. A map is a data structure that maps keys to values. One map is the
default map, but the embedded WXS grid can have several maps.
The cache uses WebSphere eXtreme
Scale dynamic maps. Any map name is allowed, apart from names that begin
with SYSTEM.BROKER, which is reserved for use by the integration node. The default map is named
SYSTEM.BROKER.DEFAULTMAP; you can use or clear this map.
- ObjectGrid® file
- An ObjectGrid XML file is used to configure the WebSphere eXtreme
Scale client. You can use this file to override WebSphere eXtreme
Scale properties. For more information about configuring clients, see
WebSphere Extreme
Scale product documentation online.
You can configure WebSphere eXtreme
Scale options
by using the WXSServer policy. For more information, see Connecting to a WebSphere eXtreme Scale grid.
You can use resource statistics and activity trace to monitor the status of the embedded WXS
grid and external grid, and to diagnose problems. You can also administer the embedded WXS
grid by using the mqsicacheadmin command.
